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Mohn N, Par M, Gubler A, Tauböck TT. Marginal integrity of prototype bioactive glass-doped resin composites in class II cavities. Clin Oral Investig 2024; 28:430. [PMID: 39012388 DOI: 10.1007/s00784-024-05824-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2024] [Accepted: 07/08/2024] [Indexed: 07/17/2024]
Abstract
OBJECTIVES This in vitro study examined the marginal integrity of experimental composite materials doped with bioactive glass (BG). MATERIALS AND METHODS Class-II MOD cavities were prepared and restored with one of the following composite materials: a commercial composite material as a reference (Filtek Supreme XTE), an experimental composite doped with BG 45S5 (C-20), and an experimental composite doped with a fluoride-containing BG (F-20). Six experimental groups (n = 8) were used, as each of the three composites was applied with (+) or without (-) a universal adhesive (Adper Scotchbond Multipurpose). All specimens were subjected to thermocycling (10,000 x, 5-55 °C) and then additionally stored in artificial saliva for eight weeks. Scanning electron micrographs of the mesial and the distal box were taken at three time points (initial, after thermocycling, and after eight weeks of storage in artificial saliva). The margins were classified as "continuous" and "non-continuous" and the percentage of continuous margins (PCM) was statistically analyzed (α = 0.05). RESULTS In most experimental groups, thermocycling led to a significant decrease in PCM, while the additional 8-week aging had no significant effect. F-20 + performed significantly better (p = 0.005) after 8 weeks storage in artificial saliva than the reference material with adhesive, while no statistically significant differences were observed at the other two time points. C-20 + exhibited significantly better PCM than the reference material with adhesive after thermocycling (p = 0.026) and after 8 weeks (p = 0.003). CONCLUSIONS Overall, the experimental composites with BG showed at least as good marginal adaptation as the commercial reference, with an indication of possible re-sealing of marginal gaps. CLINICAL RELEVANCE Maintaining or improving the marginal integrity of composite restorations is important to prevent microleakage and its likely consequences such as pulp irritation and secondary caries.
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Affiliation(s)
- Nike Mohn
- Department of Conservative and Preventive Dentistry, Center for Dental Medicine, University of Zurich, Plattenstrasse 11, Zurich, Switzerland
| | - Matej Par
- Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Gunduliceva 5, Zagreb, Croatia.
| | - Andrea Gubler
- Department of Conservative and Preventive Dentistry, Center for Dental Medicine, University of Zurich, Plattenstrasse 11, Zurich, Switzerland
| | - Tobias T Tauböck
- Department of Conservative and Preventive Dentistry, Center for Dental Medicine, University of Zurich, Plattenstrasse 11, Zurich, Switzerland
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Kirste G, Contreras Jaimes A, de Pablos-Martín A, de Souza E Silva JM, Massera J, Hill RG, Brauer DS. Bioactive glass-ceramics containing fluorapatite, xonotlite, cuspidine and wollastonite form apatite faster than their corresponding glasses. Sci Rep 2024; 14:3997. [PMID: 38369547 PMCID: PMC10874964 DOI: 10.1038/s41598-024-54228-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 02/09/2024] [Indexed: 02/20/2024] Open
Abstract
Crystallisation of bioactive glasses has been claimed to negatively affect the ion release from bioactive glasses. Here, we compare ion release and mineralisation in Tris-HCl buffer solution for a series of glass-ceramics and their parent glasses in the system SiO2-CaO-P2O5-CaF2. Time-resolved X-ray diffraction analysis of glass-ceramic degradation, including quantification of crystal fractions by full pattern refinement, show that the glass-ceramics precipitated apatite faster than the corresponding glasses, in agreement with faster ion release from the glass-ceramics. Imaging by transmission electron microscopy and X-ray nano-computed tomography suggest that this accelerated degradation may be caused by the presence of nano-sized channels along the internal crystal/glassy matrix interfaces. In addition, the presence of crystalline fluorapatite in the glass-ceramics facilitated apatite nucleation and crystallisation during immersion. These results suggest that the popular view of bioactive glass crystallisation being a disadvantage for degradation, apatite formation and, subsequently, bioactivity may depend on the actual system study and, thus, has to be reconsidered.
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Affiliation(s)
- Gloria Kirste
- Otto Schott Institute of Materials Research, Friedrich Schiller University, Lessingstr. 12 (AWZ), 07743, Jena, Germany
- Leibniz Institute for Solid State and Materials Research (IFW), Helmholtzstr. 20, 01069, Dresden, Germany
| | - Altair Contreras Jaimes
- Otto Schott Institute of Materials Research, Friedrich Schiller University, Lessingstr. 12 (AWZ), 07743, Jena, Germany
| | - Araceli de Pablos-Martín
- Otto Schott Institute of Materials Research, Friedrich Schiller University, Lessingstr. 12 (AWZ), 07743, Jena, Germany
- Fraunhofer Institute for Microstructure of Materials and Systems IMWS, Walter-Hülse-Str. 1, 06120, Halle, Germany
- Wilhelm Dyckerhoff Institut, Dyckerhoff GmbH, Dyckerhoffstraße 7, 65203, Wiesbaden, Germany
| | - Juliana Martins de Souza E Silva
- Fraunhofer Institute for Microstructure of Materials and Systems IMWS, Walter-Hülse-Str. 1, 06120, Halle, Germany
- Institute of Physics, Martin Luther University Halle-Wittenberg, Heinrich-Damerow-Str. 4, 06120, Halle, Germany
| | - Jonathan Massera
- Faculty of Medicine and Health Technology, Tampere University, Korkeakoulunkatu 3, 33720, Tampere, Finland
| | - Robert G Hill
- Dental Physical Sciences, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Delia S Brauer
- Otto Schott Institute of Materials Research, Friedrich Schiller University, Lessingstr. 12 (AWZ), 07743, Jena, Germany.
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Jin C, Zhang M, Lin J. Microcrystallization Effects in Borosilicate Bioactive Glasses: Controllable Release of Bioactive Elements and In Vitro Degradation Properties. MATERIALS (BASEL, SWITZERLAND) 2023; 17:32. [PMID: 38203886 PMCID: PMC10779850 DOI: 10.3390/ma17010032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/17/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024]
Abstract
Borosilicate bioactive glasses exhibit excellent bioactivity and degradation properties; however, they suffer from the rapid release of bioactive elements at the initial stage of their degradation. Excessive local concentrations (such as those of B) can affect cell proliferation. Moreover, the degradation and mineralization ability of these glasses deteriorate at the later stages. Aiming to balance the release of bioactive elements during the whole process, herein, a borosilicate bioactive glass 18SiO2-6Na2O-8K2O-8MgO-22CaO-2P2O5-36B2O3 (mol%) was prepared using the melting method. Further, the effects of microcrystallization on the release of bioactive elements and in vitro degradation were studied. Results show that after heat treatment at temperatures over 620 °C, multiple microcrystalline phases, including Ca2SiO4, CaB2O4, and CaMgB2O5, form in the glass. The glass samples heat-treated within the range of 620-640 °C undergo appropriate devitrification degrees, decelerating the rate of pH increase of the immersion solution during the initial stage in comparison to those treated at lower temperatures. This results in a more continuous release of all bioactive elements and allows better control of the overall degradation. Contrarily, the more extensive devitrification degrees of glass samples heat-treated at higher temperatures reverse the pH increase and degradation trends. Since bone marrow mesenchymal stem cells and mouse embryonic osteoblast cells are pH-sensitive, inducing a suitable degree of devitrification proved to favor cell viability and enhance the mineralization capacity. Thus, different microcrystallization degrees provide new approaches for controlling the degradation and release of bioactive elements, resulting in the simultaneous enhancement of biosafety and bioactivity.
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Affiliation(s)
- Chengyun Jin
- School of Materials Science and Engineering, Tongji University, Shanghai 201804, China; (C.J.); (M.Z.)
| | - Minhui Zhang
- School of Materials Science and Engineering, Tongji University, Shanghai 201804, China; (C.J.); (M.Z.)
| | - Jian Lin
- School of Materials Science and Engineering, Tongji University, Shanghai 201804, China; (C.J.); (M.Z.)
- Key Laboratory of Advanced Civil Engineering Materials, Ministry of Education, Tongji University, Shanghai 200092, China
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4
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Chen X, Liu Y, Zhao Y, Ouyang Z, Zhou H, Li L, Li L, Li F, Xie X, Hill RG, Wang S, Chen X. Halide-containing bioactive glasses enhance osteogenesis in vitro and in vivo. BIOMATERIALS ADVANCES 2022; 143:213173. [PMID: 36356468 DOI: 10.1016/j.bioadv.2022.213173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 10/17/2022] [Accepted: 10/23/2022] [Indexed: 06/16/2023]
Abstract
The application of bone substitutes to reconstruct bone defects is a strategy for repairing alveolar bone loss caused by periodontal disease. Bioactive glasses (BGs) are attractive synthetic bone substitutes owing to their abilities to degrade, form bone-like mineral and stimulate bone regeneration. Our previous studies showed that the incorporation of fluoride into alkali-free bioactive silicate glass promoted osteogenesis to some extent in vitro, while the incorporation of chloride facilitated glass degradation and accelerated the formation of hydroxyapatite. However, whether there is a synergistic effect of incorporating fluoride and chloride on further enhancement of osteogenesis and angiogenesis in vitro and in vivo was not known. Therefore, we synthesized three halide-containing BGs with fluoride only, or chloride only, or mixed fluoride and chloride, investigated their physicochemical properties and osteogenic and angiogenic effects both in vitro and in vivo. The results showed that the addition of both fluoride and chloride in a bioactive silicate glass could combine the structural roles of both, leading to a faster apatite formation than the glass with the presence of fluoride only and a more stable fluorapatite formation than the glass with the presence of chloride only, which formed hydroxyapatite upon immersion. The studied BGs were cytocompatible, as suggested by the cytotoxicity evaluation of hPDLSCs cultivated in the extracted BGs-conditioned culture media. More importantly, these BGs stimulated osteogenic differentiation of hPDLSCs without adding growth factors as indicated by the fact that BGs-conditioned media up-regulated the expression of BMP-2, OPN and VEGF of hPDLSCs and promoted the formation of bone nodules and collagen in vitro. By comparison, the incorporation of fluoride facilitated the expression of osteogenic-related biomarkers and bone nodule formation preferentially, while the incorporation of chloride induced the expression of angiogenic-related biomarkers and collagen formation. The in vivo investigation results demonstrated that the developed halide-containing BGs accelerated the process of bone regeneration, while the glass with mixed fluoride and chloride showed the most significant promotion effect among the three BGs. Therefore, our findings revealed a synergistic effect of incorporating fluoride and chloride into a BG on osteogenesis and angiogenesis in vitro and in vivo and highlighted the potential of fluoride and chloride containing bioactive glasses being bone substitutes for clinical use.
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Affiliation(s)
- Xiaojing Chen
- Xiangya School of Stomatology, Central South University, Changsha 410008, Hunan, China; Xiangya Stomatological Hospital, Central South University, Changsha 410008, Hunan, China; Hunan Key Laboratory of Oral Health Research, Central South University, Changsha 410008, Hunan, China; Academician Workstation for Oral-maxillofacial and Regenerative Medicine, Central South University, Changsha 410008, Hunan, China.
| | - Yuting Liu
- Xiangya School of Stomatology, Central South University, Changsha 410008, Hunan, China; Xiangya Stomatological Hospital, Central South University, Changsha 410008, Hunan, China; Hunan Key Laboratory of Oral Health Research, Central South University, Changsha 410008, Hunan, China
| | - Yue Zhao
- Xiangya School of Stomatology, Central South University, Changsha 410008, Hunan, China; Xiangya Stomatological Hospital, Central South University, Changsha 410008, Hunan, China; Hunan Key Laboratory of Oral Health Research, Central South University, Changsha 410008, Hunan, China
| | - Zechi Ouyang
- Xiangya School of Stomatology, Central South University, Changsha 410008, Hunan, China; Xiangya Stomatological Hospital, Central South University, Changsha 410008, Hunan, China; Hunan Key Laboratory of Oral Health Research, Central South University, Changsha 410008, Hunan, China
| | - Hongbo Zhou
- Xiangya School of Stomatology, Central South University, Changsha 410008, Hunan, China; Xiangya Stomatological Hospital, Central South University, Changsha 410008, Hunan, China; Hunan Key Laboratory of Oral Health Research, Central South University, Changsha 410008, Hunan, China
| | - Lisha Li
- Xiangya School of Stomatology, Central South University, Changsha 410008, Hunan, China; Xiangya Stomatological Hospital, Central South University, Changsha 410008, Hunan, China; Hunan Key Laboratory of Oral Health Research, Central South University, Changsha 410008, Hunan, China
| | - Long Li
- Xiangya School of Stomatology, Central South University, Changsha 410008, Hunan, China; Xiangya Stomatological Hospital, Central South University, Changsha 410008, Hunan, China; Hunan Key Laboratory of Oral Health Research, Central South University, Changsha 410008, Hunan, China
| | - Fenghua Li
- Xiangya School of Stomatology, Central South University, Changsha 410008, Hunan, China; Xiangya Stomatological Hospital, Central South University, Changsha 410008, Hunan, China; Hunan Key Laboratory of Oral Health Research, Central South University, Changsha 410008, Hunan, China
| | - Xiaoli Xie
- Xiangya School of Stomatology, Central South University, Changsha 410008, Hunan, China; Xiangya Stomatological Hospital, Central South University, Changsha 410008, Hunan, China; Hunan Key Laboratory of Oral Health Research, Central South University, Changsha 410008, Hunan, China
| | - Robert G Hill
- Institute of Dentistry, Dental Physical Sciences Unit, Barts & The London School of Medicine and Dentistry, Queen Mary University of London, UK
| | - Songlin Wang
- Academician Workstation for Oral-maxillofacial and Regenerative Medicine, Central South University, Changsha 410008, Hunan, China; Beijing Laboratory of Oral Health, Capital Medical University, Beijing 100069, China; Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China.
| | - Xiaohui Chen
- Division of Dentistry, School of Medical Sciences, The University of Manchester, Manchester, UK.
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Chen X, Wang M, Kenny C, Chen X, Karpukhina N, Hill RG. Novel Fluoride- and Chloride-containing Bioactive Glasses for Use in Air Abrasion. J Dent 2022; 125:104252. [PMID: 36030643 DOI: 10.1016/j.jdent.2022.104252] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 08/06/2022] [Accepted: 08/10/2022] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES To investigate the degradation, fluorapatite formation, biological safety and cutting efficiency on dentine of the mixed fluoride- and chloride-containing bioactive glasses (BGs). METHODS Two series of mixed fluoride- and chloride-containing glasses (GPFCl and GPF2.3Cl series) were synthesized using a melt-quench method. Glass transition temperature (Tg) and the bioactivity in term of glass degradation and fluorapatite formation were evaluated in Tris buffer solution. The cutting efficiency of the powdered BGs (GPF2.3Cl series) on dentine via air abrasion was investigated using white light profilometry and scanning electron microscope. The cytotoxicity of GPF2.3Cl series on human periodontal ligament stem cells (hPLSCs) and oral fibroblasts (OFB) were examined by MTT. RESULTS These BGs are highly degradable and able to form fluorapatite within 3h of immersion. The formation of CaF2 was also found in the high fluoride-containing BGs. The faster glass degradation was evidenced in the BGs with higher chloride. A significant reduction of Tg from 790°C to 463°C was seen with increasing in calcium halide content. Air abrasion on dentine using the low and intermediate chloride-containing glasses demonstrates clear depressions, while no depression was found using the high chloride-containing glass. Moreover, the studied BGs showed no cytotoxicity to hPLSCs and OFB. CONCLUSIONS The glasses with mixed fluoride and chloride integrate the benefits from the presence of both, showing rapid glass degradation, fast fluorapatite formation, excellent biocompatibility and controllable hardness to provide a selective cutting efficiency on dentine. CLINICAL SIGNIFICANCE The developed BGs air abrasive with tunable hardness by varying chloride content can selectively cut different dental tissues. In clinic, a relatively hard BG is of great interest for caries preparation, while a soft glass is attractive for tooth cleaning.
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Affiliation(s)
- Xiaojing Chen
- Hunan Key Laboratory of Oral Health Research & Academician Workstation for Oral-maxillofacial and Regenerative Medicine & Xiangya Stomatological Hospital & Xiangya School of Stomatology, Central South University, Changsha, 410008, Hunan, China; Institute of Dentistry, Dental Physical Sciences Unit, Barts & The London School of Medicine and Dentistry, Queen Mary University of London, E1 4NS, UK.
| | - Minyuan Wang
- Hunan Key Laboratory of Oral Health Research & Academician Workstation for Oral-maxillofacial and Regenerative Medicine & Xiangya Stomatological Hospital & Xiangya School of Stomatology, Central South University, Changsha, 410008, Hunan, China
| | - Catherine Kenny
- Institute of Dentistry, Dental Physical Sciences Unit, Barts & The London School of Medicine and Dentistry, Queen Mary University of London, E1 4NS, UK
| | - Xiaohui Chen
- Division of Dentistry, School of Medical Sciences, The University of Manchester, Manchester, M13 9PL, UK
| | - Natalia Karpukhina
- Institute of Dentistry, Dental Physical Sciences Unit, Barts & The London School of Medicine and Dentistry, Queen Mary University of London, E1 4NS, UK
| | - Robert G Hill
- Institute of Dentistry, Dental Physical Sciences Unit, Barts & The London School of Medicine and Dentistry, Queen Mary University of London, E1 4NS, UK
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6
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Workie AB, Shih SJ. A study of bioactive glass-ceramic's mechanical properties, apatite formation, and medical applications. RSC Adv 2022; 12:23143-23152. [PMID: 36090402 PMCID: PMC9380540 DOI: 10.1039/d2ra03235j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 08/02/2022] [Indexed: 11/21/2022] Open
Abstract
Apparently, bioactive glass-ceramics are made by doing a number of steps, such as creating a microstructure from dispersed crystals within the residual glass, which provides high bending strength, and apatite crystallizes on surfaces of glass-ceramics when calcium ions are present in the blood. Apatite crystals grow on the glass and ceramic surfaces due to the hydrated silica. These materials are biocompatible with living bone in a matter of weeks, don't weaken mechanically or histologically, and exhibit good osteointegration as well as mechanical properties that are therapeutically relevant, such as fracture toughness and flexural strength. As part of this study, we examined mechanical properties, process mechanisms involved in apatite formation, and potential applications for bioactive glass-ceramic in orthopedic surgery, including load-bearing devices.
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Affiliation(s)
- Andualem Belachew Workie
- Faculty of Materials Science and Engineering, Bahir Dar Institute of Technology, Bahir Dar University P. O. Box 26 Bahir Dar Ethiopia
- Department of Materials Science and Engineering, National Taiwan University of Science and Technology 43 Sec. 4 Keelung Road Taipei 10607 Taiwan
| | - Shao-Ju Shih
- Department of Materials Science and Engineering, National Taiwan University of Science and Technology 43 Sec. 4 Keelung Road Taipei 10607 Taiwan
- Department of Fragrance and Cosmetic Science, Kaohsiung Medical University No. 100, Shih-Chuan 1st Road Kaohsiung 80708 Taiwan
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Jaimes ATC, Kirste G, de Pablos-Martín A, Selle S, de Souza E Silva JM, Massera J, Karpukhina N, Hill RG, Brauer DS. Nano-imaging confirms improved apatite precipitation for high phosphate/silicate ratio bioactive glasses. Sci Rep 2021; 11:19464. [PMID: 34593912 PMCID: PMC8484619 DOI: 10.1038/s41598-021-98863-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 08/18/2021] [Indexed: 11/21/2022] Open
Abstract
Bioactive glasses convert to a biomimetic apatite when in contact with physiological solutions; however, the number and type of phases precipitating depends on glass composition and reactivity. This process is typically followed by X-ray diffraction and infrared spectroscopy. Here, we visualise surface mineralisation in a series of sodium-free bioactive glasses, using transmission electron microscopy (TEM) with energy-dispersive X-ray spectroscopy (EDXS) and X-ray nano-computed tomography (nano-CT). In the glasses, the phosphate content was increased while adding stoichiometric amounts of calcium to maintain phosphate in an orthophosphate environment in the glass. Calcium fluoride was added to keep the melting temperature low. TEM brought to light the presence of phosphate clustering and nearly crystalline calcium fluoride environments in the glasses. A combination of analytical methods, including solid-state NMR, shows how with increasing phosphate content in the glass, precipitation of calcium fluoride during immersion is superseded by fluorapatite precipitation. Nano-CT gives insight into bioactive glass particle morphology after immersion, while TEM illustrates how compositional changes in the glass affect microstructure at a sub-micron to nanometre-level.
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Affiliation(s)
- Altair T Contreras Jaimes
- Otto Schott Institute of Materials Research, Friedrich Schiller University, Fraunhoferstr. 6, 07743, Jena, Germany
| | - Gloria Kirste
- Otto Schott Institute of Materials Research, Friedrich Schiller University, Fraunhoferstr. 6, 07743, Jena, Germany.,Leibniz Institute for Solid State and Materials Research Dresden, Helmholtzstr. 20, 01069, Dresden, Germany
| | - Araceli de Pablos-Martín
- Otto Schott Institute of Materials Research, Friedrich Schiller University, Fraunhoferstr. 6, 07743, Jena, Germany. .,Fraunhofer Institute for Microstructure of Materials and Systems IMWS, Walter-Hülse-Str. 1, 06120, Halle, Germany.
| | - Susanne Selle
- Fraunhofer Institute for Microstructure of Materials and Systems IMWS, Walter-Hülse-Str. 1, 06120, Halle, Germany
| | - Juliana Martins de Souza E Silva
- Fraunhofer Institute for Microstructure of Materials and Systems IMWS, Walter-Hülse-Str. 1, 06120, Halle, Germany.,Institute of Physics, Martin Luther University Halle-Wittenberg, Heinrich-Damerow-Str. 4, 06120, Halle, Germany
| | - Jonathan Massera
- Faculty of Medicine and Health Technology, Tampere University, Korkeakoulunkatu 3, 33720, Tampere, Finland
| | - Natalia Karpukhina
- Dental Physical Sciences, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Robert G Hill
- Dental Physical Sciences, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
| | - Delia S Brauer
- Otto Schott Institute of Materials Research, Friedrich Schiller University, Fraunhoferstr. 6, 07743, Jena, Germany.
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Tiskaya M, Shahid S, Gillam D, Hill R. The use of bioactive glass (BAG) in dental composites: A critical review. Dent Mater 2021; 37:296-310. [PMID: 33441250 DOI: 10.1016/j.dental.2020.11.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 08/23/2020] [Accepted: 11/21/2020] [Indexed: 12/16/2022]
Abstract
OBJECTIVE In recent years, numerous studies have analyzed the role of bioactive glass (BAG) as remineralizing additives in dental restorative composites. This current review provides a critical analysis of the existing literature, particularly focusing on BAGs prepared via the melt-quench route that form an "apatite-like" phase when immersed in physiological-like solutions. METHODS Online databases (Science Direct, PubMed and Google Scholar) were used to collect data published from 1962 to 2020. The research papers were analyzed and the relevant papers were selected for this review. Sol-gel BAGs were not included in this review since it is not a cost-effective manufacturing technique that can be upscaled and is difficult to incorporate fluoride. RESULTS BAGs release Ca2+, PO43- and F- ions, raise the pH and form apatite. There are numerous published papers on the bioactivity of BAGs, but the different glass compositions, volume fractions, particle sizes, immersion media, time points, and the characterization techniques used, make comparison difficult. Several papers only use certain characterization techniques that do not provide a full picture of the behavior of the glass. It was noted that in most studies, mechanical properties were measured on dry samples, which does not replicate the conditions in the oral environment. Therefore, it is recommended that samples should be immersed for longer time periods in physiological solutions to mimic clinical environments. SIGNIFICANCE BAGs present major benefits in dentistry, especially their capacity to form apatite, which could potentially fill any marginal gaps produced due to polymerization shrinkage.
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Affiliation(s)
- Melissa Tiskaya
- Queen Mary University of London, Barts & The London School of Medicine and Dentistry, Institute of Dentistry, Centre for Oral Bioengineering, Mile End Road, London E1 4NS, UK.
| | - Saroash Shahid
- Queen Mary University of London, Barts & The London School of Medicine and Dentistry, Institute of Dentistry, Centre for Oral Bioengineering, Mile End Road, London E1 4NS, UK
| | - David Gillam
- Queen Mary University of London, Barts & The London School of Medicine and Dentistry, Institute of Dentistry, Centre for Oral Bioengineering, Mile End Road, London E1 4NS, UK
| | - Robert Hill
- Queen Mary University of London, Barts & The London School of Medicine and Dentistry, Institute of Dentistry, Centre for Oral Bioengineering, Mile End Road, London E1 4NS, UK
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9
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Nommeots-Nomm A, Houaoui A, Pradeepan Packiyanathar A, Chen X, Hokka M, Hill R, Pauthe E, Petit L, Boissière M, Massera J. Phosphate/oxyfluorophosphate glass crystallization and its impact on dissolution and cytotoxicity. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 117:111269. [PMID: 32919633 DOI: 10.1016/j.msec.2020.111269] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 07/03/2020] [Accepted: 07/04/2020] [Indexed: 11/19/2022]
Abstract
The role of fluorine in bioactive glasses is of interest due to the potential of precipitating fluorapatite, a phase with higher chemical resistance than the typical hydroxyapatite precipitated from oxide bioactive glasses. However, the introduction of fluorine in silicate bioactive glasses was found deleterious to the bioactivity of the glass. Here, phosphate glasses with the composition 75NaPO3-(25-x) CaO-xCaF2 (in mol%), with x = 0-20 and glass-ceramics were investigated to evaluate their potential as substitutes to the traditional silicate bioactive glass. An increase in CaF2 substitution for CaO led to an increase in the glass solubility, due to an increase in highly soluble F(M)n species (where M is a cation) and to an increased polymerization of the phosphate network. Structural analysis reveals the formation of FP bonds, in addition to the F(M)n species, in the glass with the higher CaF2 content. Furthermore, with heat treatment, CaF2 crystals precipitate within the bulk in the newly developed glass, when x = 20. This bulk crystallization reduces the glass dissolution without compromising the precipitation of a reactive layer at the glass surface. Finally, in vitro cell tests were performed using MC3T3 pre-osteoblastic cells. While the substitution of CaF2 for CaO led to an increased cytotoxicity, the controlled crystallization of the fluorine containing glasses decreased such cytotoxicity to similar values than traditional bioactive phosphate glass (x0). This study reports on new oxyfluorophosphate glass and glass-ceramics able, not only, to precipitate a Ca-P reactive layer but also to be processed into glass-ceramics with controlled crystal size, density and cellular activity. STATEMENT OF SIGNIFICANCE: Uncontrolled crystallization of bioactive glasses has negative effect on the materials' bioactivity. While in silicate glass the bioactivity is solely reduced, in phosphate glasses it is often completely suppressed. Furthermore, the need for fluorine containing bioactive glasses, not only for use in bone reconstruction but also in toothpaste as emerged. The addition of F in both silicate and phosphate has led to challenges due the lack of Si-F or P-F bonds, generally leading to a decrease in bioactivity. Here, we developed a bioactive invert phosphate glass where up to 20 mol% of CaO was replaced with CaF2. In the new developed glasses, NMR demonstrated formation of P-F bonds. The content of fluorine was tailored to induce CaF2 bulk crystallization. Overall an increase in F was associated with an increase network connectivity. In turns it led to an increased dissolution rate which was linked to a higher cytotoxicity. Upon (partial to full) surface crystallization of the F-free glass, the bioactivity (ability to form a reactive layer) was loss and the cytotoxicity again increased due to the rapid dissolution of one crystal phase and of the remaining amorphous phase. On another hand, the controlled bulk precipitation of CaF2 crystals, in the F-containing glass, was associated with a reduced cytotoxicity. The new oxyfluorophosphate glass-ceramic developed is promising for application in the biomedical field.
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Affiliation(s)
- A Nommeots-Nomm
- Tampere University, Faculty of Medicine and Health Technology, Laboratory of Biomaterials and Tissue Engineering, Korkeakoulunkatu 3, 33720 Tampere, Finland
| | - A Houaoui
- Biomaterials for Health Research Group, ERRMECe, Equipe de recherche sur les Relations Matrice Extracellulaire-Cellules (EA1391), Institut des matériaux I-MAT (FD4122), CY Tech, CY Cergy Paris University, Maison Internationale de la Recherche (MIR), rue Descartes, 95001 Neuville sur Oise cedex, France
| | - A Pradeepan Packiyanathar
- Biomaterials for Health Research Group, ERRMECe, Equipe de recherche sur les Relations Matrice Extracellulaire-Cellules (EA1391), Institut des matériaux I-MAT (FD4122), CY Tech, CY Cergy Paris University, Maison Internationale de la Recherche (MIR), rue Descartes, 95001 Neuville sur Oise cedex, France
| | - X Chen
- Hunan Key Laboratory of Oral Health Research & Hunan 3D Printing Engineering Research Center of Oral Care Xiangya Stomatological Hospital & Xiangya School of Stomatology, Central South University, Changsha, 410008, Hunan, China
| | - M Hokka
- Tampere University of Technology, Laboratory of Material Sciences, Korkeakoulunkatu 3, 33720 Tampere, Finland
| | - R Hill
- Dental Physical Sciences, Institute of Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - E Pauthe
- Biomaterials for Health Research Group, ERRMECe, Equipe de recherche sur les Relations Matrice Extracellulaire-Cellules (EA1391), Institut des matériaux I-MAT (FD4122), CY Tech, CY Cergy Paris University, Maison Internationale de la Recherche (MIR), rue Descartes, 95001 Neuville sur Oise cedex, France
| | - L Petit
- Tampere University of Technology, Laboratory of Photonics, Korkeakoulunkatu 3, 33720 Tampere, Finland
| | - M Boissière
- Biomaterials for Health Research Group, ERRMECe, Equipe de recherche sur les Relations Matrice Extracellulaire-Cellules (EA1391), Institut des matériaux I-MAT (FD4122), CY Tech, CY Cergy Paris University, Maison Internationale de la Recherche (MIR), rue Descartes, 95001 Neuville sur Oise cedex, France
| | - J Massera
- Tampere University, Faculty of Medicine and Health Technology, Laboratory of Biomaterials and Tissue Engineering, Korkeakoulunkatu 3, 33720 Tampere, Finland.
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10
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Mozafari M, Banijamali S, Baino F, Kargozar S, Hill RG. Calcium carbonate: Adored and ignored in bioactivity assessment. Acta Biomater 2019; 91:35-47. [PMID: 31004843 DOI: 10.1016/j.actbio.2019.04.039] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 04/10/2019] [Accepted: 04/12/2019] [Indexed: 11/26/2022]
Abstract
The title of this article could sound a bit curious to some readers since a layer of apatite - and not calcium carbonate - is well-known to form on the surface of bioactive glasses upon immersion in simulated body fluids. However, calcium carbonate (commonly reported as calcite crystals) can form on the surface of bioactive glasses as well, instead of or in competition with hydroxyapatite, during in vitro tests. Major factors that govern calcium carbonate formation are a high concentration of Ca2+ ions in the testing solution - and, in this regard, glass composition/texture and type of medium play key roles - along with the volume of solution used during in vitro tests. To date, this phenomenon has received relatively little attention and is still partly unexplored. This article provides a critical overview of the available literature on this topic in order to stimulate constructive discussion among biomaterials scientists and further research for better understanding the mechanisms involved in glass bioactivity. STATEMENT OF SIGNIFICANCE: A literature search indicates that a layer of apatite - and not calcium carbonate - is well known to form on the surface of biomaterials during the bioactivity assessment. However, calcium carbonate can form on the surface as well, instead of or in competition with apatite. To date, this phenomenon has received relatively little attention and is still partly unexplored. This review provides a critical overview of the available literature on this topic in order to stimulate constructive discussions that can be further useful for clinical success.
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11
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Pedone A, Chen X, Hill RG, Karpukhina N. Molecular Dynamics Investigation of Halide-Containing Phospho-Silicate Bioactive Glasses. J Phys Chem B 2018; 122:2940-2948. [DOI: 10.1021/acs.jpcb.8b00547] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alfonso Pedone
- Dipartimento di Scienze Chimiche e Geologiche, Università di Modena e Reggio Emilia, Via G. Campi 103, 41125 Modena, Italy
| | - Xiaojing Chen
- Xiangya Stomatological Hospital & School of Stomatology, Central South University, Changsha, Hunan 410078, P.R. China
- Dental Physical Sciences, Institute of Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Robert G. Hill
- Dental Physical Sciences, Institute of Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Natalia Karpukhina
- Dental Physical Sciences, Institute of Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
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12
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Chen X, Karpukhina N, Brauer DS, Hill RG. High chloride content calcium silicate glasses. Phys Chem Chem Phys 2018; 19:7078-7085. [PMID: 28225127 DOI: 10.1039/c6cp07905a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Chloride is known to volatilize from silicate glass melts and until now, only a limited number of studies on oxychloride silicate glasses have been reported. In this paper we have synthesized silicate glasses that retain large amounts of CaCl2. The CaCl2 has been added to the calcium metasilicate composition (CaO·SiO2). Glasses were produced via a melt quench route and an average of 70% of the chloride was retained after melting. Up to 31.6 mol% CaCl2 has been successfully incorporated into these silicate glasses without the occurrence of crystallization. 29Si MAS-NMR spectra showed the silicon being present mainly as a Q2 silicate species. This suggests that chloride formed Cl-Ca(n) species, rather than Si-Cl bonds. Upon increasing the CaCl2 content, the Tg reduced markedly from 782 °C to 370 °C. Glass density and glass crystallization temperature decreased linearly with an increase in the CaCl2 content. However, both linear regressions revealed a breakpoint at a CaCl2 content just below 20 mol%. This might be attributed to a significant change in the structure and is also correlated with the nature of the crystallizing phases formed upon heat treatment. The glasses with less than 19.2 mol% CaCl2 crystallized to wollastonite, whilst the compositions with CaCl2 content equal to or greater than 19.2 mol% are thought to crystallize to CaCl2. In practice, the crystallization of CaCl2 could not occur until the crystallization temperature fell below the melting point of CaCl2. The implications of the results along with the high chloride retention are discussed.
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Affiliation(s)
- Xiaojing Chen
- Dental Physical Sciences, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
| | - Natalia Karpukhina
- Dental Physical Sciences, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
| | - Delia S Brauer
- Otto-Schott-Institut, Friedrich-Schiller-Universität, Fraunhoferstr. 6, Jena 07743, Germany
| | - Robert G Hill
- Dental Physical Sciences, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
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13
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New Insight into Mixing Fluoride and Chloride in Bioactive Silicate Glasses. Sci Rep 2018; 8:1316. [PMID: 29358590 PMCID: PMC5778077 DOI: 10.1038/s41598-018-19544-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 12/21/2017] [Indexed: 11/18/2022] Open
Abstract
Adding fluoride into bioactive glasses leads to fluorapatite formation and a decrease in glass transition temperature. Recently, chloride has been introduced into glasses as an alternative to fluoride. The presence of the large chloride ion lowers glass crystallisation tendency and increases glass molar volume, which effectively facilitates glass degradation and bone-bonding apatite-like layer formation. However, there is no information regarding the effect of mixing fluoride and chloride on the glass structure and properties. This study aims to synthesize mixed fluoride and chloride containing bioactive glasses; investigate the structural role of fluoride and chloride and their effects on glass properties. The chloride content measurements reveal that 77–90% of chloride was retained in these Q2 type glasses. Glass transition temperature reduced markedly with an increase in CaX2 (X = F + Cl) content, while the glass molar volume increased. 29Si MAS-NMR results show that the incorporation of mixed fluoride and chloride did not cause significant change in the polymerization of the silicate network and no detectable concentration of Si-F/Cl bands were present. This agrees with 19F NMR spectra showing that F existed as F-Ca(n) species.
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14
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Chen X, Chen X, Brauer DS, Wilson RM, Law RV, Hill RG, Karpukhina N. Sodium Is Not Essential for High Bioactivity of Glasses. INTERNATIONAL JOURNAL OF APPLIED GLASS SCIENCE 2017; 8:428-437. [PMID: 29271977 PMCID: PMC5736107 DOI: 10.1111/ijag.12323] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This study aims to demonstrate that excellent bioactivity of glass can be achieved without the presence of an alkali metal component in glass composition. In vitro bioactivity of two sodium-free glasses based on the quaternary system SiO2-P2O5-CaO-CaF2 with 0 and 4.5 mol% CaF2 content was investigated and compared with the sodium containing glasses with equivalent amount of CaF2. The formation of apatite after immersion in Tris buffer was followed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), 31P and 19F solid state MAS-NMR. The dissolution study was completed by ion release measurements in Tris buffer. The results show that sodium free bioactive glasses formed apatite at 3 hours of immersion in Tris buffer, which is as fast as the corresponding sodium containing composition. This signifies that sodium is not an essential component in bioactive glasses and it is possible to make equally degradable bioactive glasses with or without sodium. The results presented here also emphasize the central role of the glass compositions design which is based on understanding of structural role of components and/or predicting the network connectivity of glasses.
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Affiliation(s)
- Xiaojing Chen
- Dental Physical Sciences, Institute of Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Xiaohui Chen
- Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester M13 9PL, United Kingdom
| | - Delia S Brauer
- Otto-Schott-Institut, Friedrich-Schiller-Universität, Fraunhoferstr. 6, Jena 07743, Germany
| | - Rory M Wilson
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Robert V Law
- Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom
| | - Robert G Hill
- Dental Physical Sciences, Institute of Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Natalia Karpukhina
- Dental Physical Sciences, Institute of Dentistry, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom
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15
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Kent NW, Blunn G, Karpukhina N, Davis G, de Godoy RF, Wilson RM, Coathup M, Onwordi L, Quak WY, Hill R. In vitro
and in vivo
study of commercial calcium phosphate cement HydroSet™. J Biomed Mater Res B Appl Biomater 2016; 106:21-30. [DOI: 10.1002/jbm.b.33809] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 10/13/2016] [Accepted: 10/16/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Niall W. Kent
- Dental Physical Sciences, Institute of Dentistry, Barts and The London School of Medicine and Dentistry; Queen Mary University of London; London E1 4NS UK
- Centre for Nature Inspired Engineering; University College London, Torrington Place; London WC1E 7JE UK
- Warwick Medical School; University of Warwick; Coventry CV4 7AL UK
| | - Gordon Blunn
- John Scales Centre for Biomedical Engineering; Institute of Orthopaedics and Musculoskeletal Science, University College London, Royal National Orthopaedic Hospital; Stanmore UK
| | - Natalia Karpukhina
- Dental Physical Sciences, Institute of Dentistry, Barts and The London School of Medicine and Dentistry; Queen Mary University of London; London E1 4NS UK
| | - Graham Davis
- Dental Physical Sciences, Institute of Dentistry, Barts and The London School of Medicine and Dentistry; Queen Mary University of London; London E1 4NS UK
| | - Roberta Ferro de Godoy
- John Scales Centre for Biomedical Engineering; Institute of Orthopaedics and Musculoskeletal Science, University College London, Royal National Orthopaedic Hospital; Stanmore UK
| | - Rory M. Wilson
- School of Engineering and Materials Science; Queen Mary University of London; London E1 4NS UK
| | - Melanie Coathup
- John Scales Centre for Biomedical Engineering; Institute of Orthopaedics and Musculoskeletal Science, University College London, Royal National Orthopaedic Hospital; Stanmore UK
| | - Lyris Onwordi
- John Scales Centre for Biomedical Engineering; Institute of Orthopaedics and Musculoskeletal Science, University College London, Royal National Orthopaedic Hospital; Stanmore UK
| | - Wen Yu Quak
- John Scales Centre for Biomedical Engineering; Institute of Orthopaedics and Musculoskeletal Science, University College London, Royal National Orthopaedic Hospital; Stanmore UK
| | - Robert Hill
- Dental Physical Sciences, Institute of Dentistry, Barts and The London School of Medicine and Dentistry; Queen Mary University of London; London E1 4NS UK
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16
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Brauer DS, Brückner R, Tylkowski M, Hupa L. Sodium-free mixed alkali bioactive glasses. BIOMEDICAL GLASSES 2016. [DOI: 10.1515/bglass-2016-0012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractTwo sodium-free mixed alkali series of bioactive glasses based on compositions Bioglass 45S5 and ICIE1, containing lithium and/or potassium as alkali ions, were prepared by a melt-quench route. Thermal properties showed the well-known mixed alkali effect, with glass transition and crystallisation temperatures and the coefficient of thermal expansion going either through a minimum or a maximum for the mixed alkali composition, resulting in a wider processing window. Ion release, by contrast, was controlled by the modifier ionic radius, with ion release rates in dynamic and static dissolution studies increasing for potassium-substituted glasses compared to the composition containing lithium as the only alkali ion. This was caused by pronounced changes in oxygen packing density and molar volume of the glasses owing to the differences in ionic radii (76 pm for Li+ and 138 pm for K+). Partially substituting one alkali for another therefore helps to improve high temperature processing of bioactive glasses and can also be used to control or tailor ion release.
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17
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Tan MHX, Hill RG, Anderson P. Comparing the Air Abrasion Cutting Efficacy of Dentine Using a Fluoride-Containing Bioactive Glass versus an Alumina Abrasive: An In Vitro Study. Int J Dent 2015; 2015:521901. [PMID: 26697067 PMCID: PMC4677207 DOI: 10.1155/2015/521901] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 11/17/2015] [Indexed: 11/18/2022] Open
Abstract
Air abrasion as a caries removal technique is less aggressive than conventional techniques and is compatible for use with adhesive restorative materials. Alumina, while being currently the most common abrasive used for cutting, has controversial health and safety issues and no remineralisation properties. The alternative, a bioactive glass, 45S5, has the advantage of promoting hard tissue remineralisation. However, 45S5 is slow as a cutting abrasive and lacks fluoride in its formulation. The aim of this study was to compare the cutting efficacy of dentine using a customised fluoride-containing bioactive glass Na0SR (38-80 μm) versus the conventional alumina abrasive (29 μm) in an air abrasion set-up. Fluoride was incorporated into Na0SR to enhance its remineralisation properties while strontium was included to increase its radiopacity. Powder outflow rate was recorded prior to the cutting tests. Principal air abrasion cutting tests were carried out on pristine ivory dentine. The abrasion depths were quantified and compared using X-ray microtomography. Na0SR was found to create deeper cavities than alumina (p < 0.05) despite its lower powder outflow rate and predictably reduced hardness. The sharper edges of the Na0SR glass particles might improve the cutting efficiency. In conclusion, Na0SR was more efficacious than alumina for air abrasion cutting of dentine.
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Affiliation(s)
- Melissa H. X. Tan
- Centre for Oral Growth and Development, Barts and The London School of Medicine and Dentistry, Unit of Dental Physical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Robert G. Hill
- Centre for Oral Growth and Development, Barts and The London School of Medicine and Dentistry, Unit of Dental Physical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Paul Anderson
- Centre for Oral Growth and Development, Barts and The London School of Medicine and Dentistry, Unit of Dental Physical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
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18
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Brauer DS. Bioactive glasses—structure and properties. Angew Chem Int Ed Engl 2015; 54:4160-81. [PMID: 25765017 DOI: 10.1002/anie.201405310] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 10/20/2014] [Indexed: 11/06/2022]
Abstract
Bioactive glasses were the first synthetic materials to show bonding to bone, and they are successfully used for bone regeneration. They can degrade in the body at a rate matching that of bone formation, and through a combination of apatite crystallization on their surface and ion release they stimulate bone cell proliferation, which results in the formation of new bone. Despite their excellent properties and although they have been in clinical use for nearly thirty years, their current range of clinical applications is still small. Latest research focuses on developing new compositions to address clinical needs, including glasses for treating osteoporosis, with antibacterial properties, or for the sintering of scaffolds with improved mechanical stability. This Review discusses how the glass structure controls the properties, and shows how a structure-based design may pave the way towards new bioactive glass implants for bone regeneration.
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Affiliation(s)
- Delia S Brauer
- Otto Schott Institute of Materials Research, Friedrich Schiller University Jena, Fraunhoferstrasse 6, 07743 Jena (Germany) http://www.brauergroup.uni-jena.de.
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19
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20
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Chen X, Karpukhina N, Brauer DS, Hill RG. Novel Highly Degradable Chloride Containing Bioactive Glasses. BIOMEDICAL GLASSES 2015. [DOI: 10.1515/bglass-2015-0010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractAddition of CaF2 to a silicate bioactive glass favours formation of fluorapatite, which is less soluble in acidic environment than hydroxyapatite. However, excess CaF2 in the glass is problematic, owing to the formation of crystalline calcium fluoride rather than fluorapatite on immersion. In this paper we investigate chloride as an alternative to fluoride in bioactive silicate glasses and in particular their bioactivity for the first time. Meltderived bioactive glasses based on SiO2-P2O5-CaO-CaCl2 with varying CaCl2 contents were synthesised and characterised by DSC. Chemical analysis of the chloride content was performed by using an ion selective electrode. Glass density was determined using Helium Pycnometry. The glass bioactivity was investigated in Tris buffer. Ion release measurements were carried out by using ICP-OES. The chemical analysis results indicated that the majority of the chloride is retained in the Q2 type silicate glasses during synthesis. Tg and glass density reduced with increasing CaCl2 content. Apatite-like phase formation was confirmed by FITR, XRD and 31P MAS-NMR. The results of the in vitro studies demonstrated that the chloride containing bioactive glasses are highly degradable and form apatite-like phase within three hours in Tris buffer and, therefore, are certainly suitable for use in remineralising toothpastes. The dissolution rate of the glass was found to increase with CaCl2 content. Faster dissolving bioactive glasses may be attractive for more resorbable bone grafts and scaffolds.
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